Generative grinding machine with rolling work or tool carrier



E W.'M|LLER I 2,364,542 GENERATIVE GRINDING MACHINE WITH ROLLING WORK ORTOOL CARRIER Filed April 8 1942 9 SheetsSheet 1 Dec. 5, 1944.

Dec. 5, 1944. E. w. ILLE R 2,364,542

GENERATIVE GRI NG MACHINE WITH ROL NG' WORK 0R TOOL CARRIER iled April8, 1942 I 9 Sheets-Sheet 2 Dec. 5, 1944. E. w; MILLER 2,364,542

GENERATIVE GRINDING MACHINE WITH ROLLING WORK OR TOOL CARRIER FiledApril 8, 1942 9 Sheets-Sheet 3 w MILLER 2,364,542

E. I GENERATIVE GRINDING MACHINE WITH ROLLING WORK OR TOOL CARRIER FiledApril 8, 1942 U 9 Sheets-Sheet 4 9 Sheets-Sheet 5 E. W. MILLERGENERATIVE GRINDING MACHINE WITH ROLLING WORK OR TOOL CARRIER ril 8,1942 Dec. 5, 1944.

Filed Ap 9 Sheets-Sheet '6 WITH ER CARRI 942 ILLER NG MACHINE WORK ORTOOL ed April 8, 1

Dec. 5, 1944. I E, w, M GENERATIVE GRINDI ROLLING Fil E. W. MILLERGENERATIV E GRINDING MACHINE WITH ROLLING WORK OR TOOL CARRIER FiledApril 8, 1942 9 Sheets-Sheet 7 De c. 5, 1944.

Dec. 5, 1944. E. w. MILLER GENERATIV E GRINDING MACHINE WITH ROLLING'WORK OR TOOL CARRIER Filed April 8, 1942 9 Sheets-Sheet 8 zzw- 7 Dec.5, 1944.

E. W. MILLER GENERATIVE GRINDING MACHI ROLLING WORK OR T Filed Aprll 8NE WITH CARRIER 942 9 Sheets-Sheet 9 Patented Dec. 5, 1944 UNITED STATESGENERATIVE GRINDING MAO- u i I" ROLLING WORK OR T DOL 'DARMKER Edward W.Miller, Springfield, Vt,v assignor to The Fellows Gear Shaper Company,Spring; field, Vt., a corporation of Vermont Application Aprilfi, 1942,Serial No. idtdfit 29 Claims. The present invention relates to machinetools and particularly machines'fOr finish generating the teeth ofgearsby the action of a grinding wheel, with a relative rolling movementbetween the work gear and grinding wheel transversely of the axis of thegear, and a relative traverse between the gear and grinding wheelgenerally lengthwise of such axis. However, it is not limited to' theart of grinding machines as distinguished from machines using othertypes of cutting or smoothing tools (such as milling cutters,

shaving cutters, lapping .or burnishing tools, etc.)

Neither is it limited to gears as the class of objects to be made orfinished by the instrumentalities of the" machine, but includes machinesfor operating on many other kinds of work piece,

such as gear shaper cutters, cams and, in general, any piece to which aprescribedshape may be imparted by relative rolling traverse between thework piece and tool, or by progression of a view taken on line formedtool. Hence, although I have herein illustrated the invention as appliedto grinding machines designed to generate involute curvesin gear teeth,gear cutter teeth, cams and the like. I wish to make it clearlyunderstood that such showing is illustrative only and is not intended tohave any limiting effect beyond that of the foregoing statement and thescope of the claims.

One of the principal'objects of the invention is to effectrectilineanmovement of a work carrier or tool carrier; or of bothsimultaneously, without the use of a sliding'oarriage or equivalentslide and by the employment of rolling members instead. A furtherobject, closely related to the foregoing, is to eifect by the samerolling action which imparts translative displacement, an angularmovement of the part so displacedin such fashion as to generate aninvolute curve. Other objects are concerned with provisions foradjustment whereby to alter the characteristics of the involute curvesgenerated by such combinations of rotation and translation, and otheradjustments whereby ta red work pieces may be generated as well as thosein which the surface elements are equidistant from the axis of angularmotion thi'oughout their length.

The drawings furnished herewith to illustrate the invention show fourmachines embodying the same principles, with variations in someparticulars from each other; and illustrate additionally some of thevarious ,shapesof grinding wheel which may be used in tl .ese and otherequivalent embodiments of the invention.

In the drawings,

Fig. 1 is a side elevation, partly broken away 56' of the invention inwhich a formed grinding- -wheel is used having a profile complemental toFig. 9 is a vertical section taken on line t-ti of Fig. 8;

Fig. 10 is a horizontal section talren .on iii-Ill of Fig. 9;

Figs. 11 and 12 are cross sections taken on lines iiii and It-i2,respectively, of Fig. 10;

Fig. 13 isa sectional end elevation of the ma= chine projected on theplane designated by the position or adjustment from that represented inFig. 12;

' Fig. 18 is a view similar to Fig. 15 of anotherform of machineembodying manyof the features of themachine shown in Figs. 7-17inclusive,

. equipped with a grinding Wheel of rack tooth profile atitscircumference, which is capable of substitution for the grindingwheels of either of 3 the preceding designs of machine;

Fig. 19 is asimilar view of another embodiment tion, of a spindle orother work or tool holder are accomplished by the novel means of thepresent invention;

Figs. 21 and 22 are further diagrams'explana tory of the fact that, bysubstitution of diflerent formers and adjustment of abutments at aninvariable ce'nter distance apart, a wide variety of line curves may begenerated by machines constructed in accordance with this invention;

Fig. 23 is a section similar to, Fig. 9 of the machine variation shownin Fig. 19;

Fig. 24 is a detail section taken on line 24-24 of Fig. 23;

Fig. 25 and Fig. 26 are sectional details of the means for indexing thework in the last mentioned machine.

Like reference characters designate the same' parts wherever they occurin all the figures.

The machine shown in Figs. 1-6 inclusive has a supporting structuresimilar in design to that of the conventional planer. It comprises abase In on which a sliding table II is mounted to reciprocate, anduprights I3 and I4 at opposite sides of the base, rising above thetable, and connected at their upper ends by a cross beam IS. The tablecarries a grinding wheel l6, and the uprights l3 and M serve to positionand guide a work supporting structure I! on which a work spindle I8 ismounted to carry a work piece IS. The work holding structure I! may beadjusted vertically to acommodate work pieces of different diameters orradii by means such as screws similar to the means by which the crossrail of a planer is adjusted.

This machine is adapted to grind to finished form and dimensions theinvolute tooth faces of wide faced gears and similar machine elements.

In performing this operation the work piece is rolled across the edge ofthe grinding wheel with the face of a tooth in contact with a face ofthe wheel; such rolling movement being compounded of lineartranslationof the gear in a direction transverse to its axis and rotation about itsaxis, at related speeds'such that the shifting ends formers 22 and 23,which extend downwardly between, and rest upon, abutments 24, 25, 26 and21. Theseabutments are arranged in pairs, the pair designated 24 and 25being in the same plane with, and engaging, the former 22, and the pairdesignated 26 and 21 being in the same plane .with and engaging theformer 23, as shown plainly by Figs.3 and 5. The members of each pairare inclined oppositely to one another with an included angle largeenough to provide a solid support for the carrier and prevent binding ofthe formers. For the generation of involute curves, the formers haveinvolute opposite contact faces 23 and 29, and the abutments have planecontact faces, these elements being of the same essential character asconjugate gear and rack tooth faces. Both formers are symmetrical atopposite sides of the median line in this embodiment, and they arearranged with their median lines in the same radial plane of the spindleand spindle carrier.

But perfect symmetry is not essential, since vari-' ations, withinlimits, can be compensated by angular adjustment of the abutments at onesideof the formers relative to those at the other ing different facecurves. For simplicity and convenience of manufacture, the two formersare duplicates of each other, and the contact faces of the correspondingabutments of both pairs are in respectively the same planes. These lastmentioned particulars, however, may be varied, within limits, withoutdeparting from the invention.

The abutments 24 and 26 are secured to the ends of a cylindrical bar 3|,and the abutments 25 and 21 are correspondingly secured to the ends of acylindrical bar 32. These bars are rotatably mounted in bearings 33 and34, respectively, in the supporting structure H, the axes of which areparallel to the axis of the work spindle holder. Their axes are also inthe same horizontal plane and are equidistant from the middle positionof the spindle holderaxis. Provision is made for adjusting theinclinations of the abutment faces for a purpose later explained-suchprovisions, in the present illustration, consisting of worms 35 and 36meshing with worm gear teeth 31 and 38 cut in the sides of thecylindrical bars 3| and 32, respectively. The threads of the two wormsare of respectively opposite hands, and are of equal lead, in order thatwhen both are turned equally in the same direction, the twoabutment-carrying bars will be turned through equal angles in relativelyopposite directions. The worms are carried by shafts 38 and, 40, whichprotrude through the end Walls of the supporting structure I1 and areaccessible through suitably disposed openings in the uprights l3 and I4to receive wrenches or cranks 'on their protruding ends, whereby theymay be rotated. One of the shafts has an extension 4| on its inner endprotruding into a socket in the contiguous end of the other shaft, inwhich it is locked against rotation by a set screw 42 threaded throughthe wall of the socket. When the screw is set up, rotation of eithershaft turns the other equally. But the screw may be loosened to permitan adjustment of either shaft, whereby to bring the abutments carried bythe respective bars into the correct angular relation.

Rotation is imparted-to the spindle carrier 2| by a worm 43 meshing witha worm gear segment 44 secured to the spindle carrier. This worm iscarried by a shaft 45 rotatably mounted in a housing which is supportedby brackets 41 on the structure ll. Rotation of the spindle carriercauses the formers 22 and 23 to rock on their respective abutments, withdisplacement of the spindle carrier transversely of its axis. Thecarrier is prevented from shifting endwise, while being sodisplaced, bya guide bar 48 fixed to the supporting structure beneath the spindlecarrier with an intermediate portion of its length extend-- ingtangentially through a. groove 48 provided in side. They are detachablysecured tothe carrier "by screws 30, as shown by Fig. 3, to permit re-,ments A and A.

the under side of the carrier. The opposite side faces of the guide bar48 and groove 49 are located in planes perpendicular to the spindlecarrier axis and are the cooperating elements which prevent endwisedisplacement of the carrier.

Displacements of the spindle carrier axis, due to the coaction ofiheformers and abutments, when the carrier is rotated, takes place in aplane which, in this instance, is horizontal. This fact is graphicallyexplained by the diagram in Fig.

20, which represents a former F, of the same character as the formerspreviously described, in three'positions of rotative cooperation withabut- It is shown by solid lines in mid position. be is the base circlefrom which the involute side faces of the former are generated, and disthe center of this base circle in mid position. The lines of action ofthe former with the abutments are then at la and I'd, respectively. Thecrossing point p of these lines of action is the pitch point of theformer, with respect to the abutments. Rocking of the former causes apitch circle pc, of which the center is at d and the circumferencepasses through the pitch point p, to roll without slip on a straightpitch line pl perpendicular to the radial line dp.

Rocking of the former in clockwise rotation to the position shown by thedashlines, shifts the center (1 to the position 11; and rockingcountenclockwise to the positio shown by dotted lines shifts center d tod. T ese three positions, and all other positions of the centerthroughout the full range of possible rocking movement, are all in thesame straight line. .Hence the displacenient of the work spindle, whichis carried by the formers of the preceding description in the samerelation thereto as the relation of center 01 to the former F of thediagram, takes place in a plane,

exactly as though it were mounted on a slide or carriage supported byelongated guideways or tracks.

This means for effecting rectilinear displacement of. the work spindleis of much practical advantage over a slide or carriage for the samepurpose. It avoids entirely the task of finishing long, straight,uninterrupted surfaces, such.

as guideways or tracks, and the mating surfaces of a slide or carriage.This alone is an important achievement, for the finishing of suchsurfaces with the necessary accuracy'is laborious and time consuming. Italso largely eliminates the sliding friction of such a carriage andguidecarrying the wheel, if shiftable transversely of the bed to bringthe grinding wheel into the required position, and the sub base 55 isprovided with adjusting screws 51 and 58, hearing against opposite endsof base 53, whereby the position of the latter may be exactly regulated.The subbase itself may be located in different positions across thewidth of the bed by placing the bolts 56 in difierent ones of the slots54. Thus both rough and fine adjustments for the wheel are provided forin correlation with the angular adjustment previously described.

In place of the plane faced wheel it here shown, a wheel of coneprofile, like that shown ways, for the coaction of the formers with theabutments is largely that of rolling.

When a grinding wheel, as represented at G, is mounted to rotate withits marginintersecting the pitch line pl and a face I parallel with theface of abutment A, (or two faces 1 and f parallel to the abutments Aand A respectively), and a gear is suitably mounted concentric with thecenter d and with teeth t and t disposed to roll across the grindingfaces I and f as the abutment is rocked, the grinding wheel generatescurves on the sides of the teeth which are involutes of the base circlebe. Curves of other base circles are similarly generated with settingsof the abutment faces and wheel faces at various inclinations to oneanother.

The principle thus explained isemployed in the machine now beingdescribed. The grinding wheel It has an active face 1 in a planeperpendicular to im axis, which may be set at variousmovement of thespindle holder and formers. I The wheel is secured to a spindle whichrotates in a housing 50, and the end of which opposite to that carryingthe wheel is coupled tonthe rotative element of a motor 5|. This motoris here shown conventionally and may be afhydraulic or electric motor ofany suitable character, types of which are well known. Housing iscoupled by pivots 52 with a base 53, whereby the inclination of thewheel face may be'varied to generate curves of different pressure anglesand base circles. The base 53 rests on a sub-base 55 which is clamped tothe bed by bolts 56 contained in the usual T-slots 54 of the bed. Thebase 53,

bring the spindle axis horizontal so that it mav carry a wheel of racktooth profile.

'By the substitution of different formers, the

face curves of which are generated from different base circles,diiferent curves may be generated in the work piece while the abutmentsremain at an invariable centerdistance from each otheran'd from thecentral position of the axis of the work. Further, by angular adjustmentof the abutments about their axes and by angular adjustment of theactive face of the grinding wheel, a considerable range of curves ofdifferent base circles may be generated with the use of the sameformers. These facts are graphically demonstrated by the diagrams shownin Figs. 21 and 22.

The bearings 33 and 34 for the bars which sup port the abutments arefixed, wherefore their axes are at a fixed distance from each other andat fixed distances from any given position of the axis of the spindlecarrier 2 l, as,for instance, the midposition of the latter axis. Thisis the case also with the work carriersand tool carriers of the otherforms of the invention described in this specification. In Figs. '21 and22 the abutments are designated by the generic characters A. and A,Sjn-Fig. 20, for simplicity, although their ositions are somewhatdifierent from those of the abutments shown in the latter figure. F, inFig.

21, and F and F in Fig. 22, represent formers.

having involute contact faces generated from tact faces are suitablylocated with respect to their several base circles so that, when theformers are symmetrically placed in tangent contact with the abutments,and in substitution for one another, while the abutments remainunchanged s to their inclinations, the centers of the several 1 basecircles will all beat the same distance from the axes of the abutments.Considering now only the full line showing of the former F and abutmentsin Fig. 21, the base circle of the former F is b'c and its, centeris at8.. In symmetrical midposition, its points of tangent contact with therespectiveabutments are at a and it, its lines of action are "a and aand its'pitch point is at p. The former F has contact faces which areinvolute curves of a base circle h s",

smaller in diameter than the base circle b'c', and having the samecenter c. It makes tangent contact with the abutments ate and a itslines of action are l' a 'and l a and its pitchpoint is D. Todistinguish the formers F and F,

which are drawn superposed in the same figure,

for purposes of comparison as well as to save space, the curves offormer F are drawn in dot and dash lines, while the periphery of formerF is drawn in full lines.

The contact faces of former F are outer convolutions of involutesgenerated from a still smaller base circle b o centered at e. The innerconvolutions of these curves are shown by dotted lines. Their tangentpoints with the abutment are at a and a their lines of action at la andI a", and the pitch point is at 12 Since the former is required to makecontact with only two abutments, the starting points of curves, whichwill sufiice to bring the centers of all the different base circles atthe same distances from the abutment axes. As is made apparent by Fig.22, the tangent points may be on any convolutionof the involute curves,and it is immaterial whether or not the opposite curves cross betweentheir points of origin and tangent points or not, and how'many timesthey may cross each other.

The diiferent tangent points a,a ,a and a,a ,a

are located at diiferent points along the faces of the abutments, andare in the middle portions of the areas over which the different formersroll. With the particular formers here shown, the work spindle carrierrolls on different pitch cylinders, of which the radii are respectivelyep', e- -p and e-p Equal angles of rotation therefore produce, withthese different formers, widely differing linear displacements of theaxis of the carrier, whereby different curves may be generated in thework.

Angular adjustments of the abutments and changes in the inclination ofthe contact face or shifted to e and the base circle bc' to bc.

The new lines of action, being tangent to the base circle in its changedlocation, are located at I a and Na, and the pitch radius e-p' and pitchcircle p'c, on which the carrier and former assemblage rolls withrespect to the abutments, change to e'p' and 12 0 respectively. (Thefact thatin this illustration the location of the point p is the samewith both positions of the abutments has no significance, since abutmentadjustments through other angles cause the crossing point of thelines'of action also to be shifted.)

Assuming that the active face or element of the grinding wheel remainsin a plane 1 parallel to the full line position of the abutment A whenthe abutment is turned to the broken line position, and is otherwiseappropriately located to act on a work piece secured to the rollingassemblage, the line of action of the work piece with respect to thegrinding wheel is We, and the curve generated in the work piece is theinvolute of a base circle bc centered at e and tangent to the line ofaction Pa. This result is obtained whether the wheel face is actually inthe plane designated by the line or at either side of it, provided onlysuch face is parallel to the abutment face and disposed to act on thatpart of the workon. which a curved surface is to be cut.

If the grinding wheel is tilted so that its active portion lies in aplane f, or a plane parallel thereto, when the abutments are in the fullline position here illustrated, the line of action of the workrelatively to the wheel is la, (perpendicular to the plane 1 and passingthrough the pitch piont p), and the curve generated in the work is theinvolute of a base circle b c centered at e and tangent to |a.

When the abutments and wheel are both adjusted through the anglesindicated, the base circle of the work becomes b 0 centered at e andtangent to Ia. Such adjustments, performed independently or inconjunction in various degrees, enable curves to be generated from basecircles of all diameters within the practical limits of adjustment.Substitutions of different formers take care of conditions beyondthese/limits of adjustment.

Completing the description of mechanical details of the machine of Fig.1, the worm shaft is rotated in alternately opposite directions by areversing electric motor 59 through a belt and pulley drive 60 and agear pair iii, the driven member of which is secured to the shaft. Themotor is reversed by switches 62 and 63 and a contactor drum 64 on ashaft 65, which is driven from shaft 45 by a worm 66 on thelatter and ameshing gear wheel 61 on shaft 65, as shown by Fig. 6. Projections 68and-69 on drum 64 are arranged to actuate the switches alternately afterthe shaft 45 has been rotated far enough to roll the spindle carrier 2|through the full swing in each direction needed for completion of a geartooth. The swing in one direction is enough to bring the work gearentirely clear of the grinding wheel to permit indexing.

A manual indexing means is here provided conspindle, with whichcooperates an index disk or plate ll keyed to the spindle and a lockingpawl I2 which enters severally the notches in the circumference of thedisk after rotation of the latter. The index disk is enclosed by ahousing II secured to the end of the spindle carrier 2|, and the lockingpawl is secured to a stud shaft 14 journaled in an offset portion of astrap 15 which surrounds the housing I3. An external hand lever 16 issecured to shaft 14 and is movable to retract pawl 12 from its normalinterlocked relation with the index plate, against the resistance of aspring pressed pin 11. The spindle may then be turned in the spindlecarrier by means of the hand wheel 10.

-A lug 18 on the housing 13 projects between an adjustable stop pin 19and a spring pressed abutment mounted in the encircling structure 15.

By means of the screw 19 the pawl 12 may be 83 to rotate a crank disk84. The' latter carries a radially adjustable crank pin 85 coupled tothe reciprocating table by a connecting rod 86 and wrist pin 81. Themounting and adjusting means forthe crank pin 85 are'of well knowncharacter.

In eifect the part 28, which has been called a work spindle carrier inthe preceding description, is itself a work holder or work carrier, towhich the spindle I8 is an adjunct oonstitutingmeans or provisions bywhich the work piece is con nected to the holder 2! to be rolled by andwith the latter across the rim of the grinding wheel. The spindle ishere made rotatable independent-' ly of the carrier 2! for the purposeof indexing the work. But so far a the function of imparting rollingmovement to the work is concerned, the spindle could as well be rigidwith the holder, or the work piece secured to the holder by any one of avariety of other means, and indexed otherwise.

it may be noted here also that the grinding wheel shown here isgenerically a cutting tool, and typifies in the generic sense allcutting or other tools capable of being used in this or a simi iarcombination for performing a desired cutting or finishing action ongears and other work pieces. The same thing is true as to the othergrinding wheels described further on in this specification.

Cutting or finishing tools of other types may be substituted for anyofsuch grinding wheel within the scope of the protection'here claimed,and are equivalent thereto. Also the gears herein shown and described aswork pieces typify work pieces of all varieties, which may be operatedon by cutting and finishing tools in any of the machines and equivalentcombinations of mechanism herein described.

Another form of machine embodying the principles hereinbefore described,with additional features, is shown in Figs. 7-17 inclusive. Here therolling work spindle carrier 9i, which corresponds to the carrier 2i,carries in its interior a work spindle 92 which is independentlyrotatable for indexing the work. An arm 93 fixed and keyed to one end ofthe carrier 9i extends outwardly therefrom to support an'outboard center94, by and between which and a center 95 in the spindle an arbor 36carrying the work piece it is supported and alined axially with the-spindle. A second arm, 91, secured to the opposite end of holder BI supportsa hydraulic motor 98, of known character, the rotor of which is conpiedwith the spindle for imparting work-indexing rotation 'thereto whenpermitted by the index controlling mechanism later described.

The carrier or work holder 9! carries on its opposite ends formers 93and lllfl which rest on and between abutments IM carried by angularlyadjustable bars I02. These formers and abutments are substantiallyidentical in construction, arrangement and function with the formers andvabutments precedently described to cause lateral displacement of thecarrier 9|, and to maintain the axis of the carrier always in the'sameplane during such displacement, when the carrier is rotated. The meansfor rotating the carrier are a worm I03 and a meshing worm gear segmentI04, secured coaxially to the carrier, like the worm 43 and gear segment44. In this instancethe worm is driven by a reversible hydraulic motorI105 instead of an electric motor. The means for reversing motor I arenot shown, it being obvious that valves controlled by the rotating worm,equivalent to the switches 32 and 63, and the switch contactors 6d and69, maybe applied to this combination to cause circulation of workingfluid alternately in opposite directions through the motor. A reversalof the guide means for the rolling carrier is here shown, consisting ofa fixed grooved bar I06, into the groov of which a rib i! on the underside of the carrier projects. Means for turning the bars W2 to shift theangle of the abutments IIiI comprise worms Mid meshing with gear teethI09 on the bars and carried by a shaft H0. A bevel gear ill on shaft lidmeshes with a bevel gear M2 on a shaft lit, which carries a. handle 1 Itaccessible for manual rotation, whereby the abutments may be adjustedwithin limits.

The housing 33 and bearings for worm tilt, the support for guide W6, andthe bearings for the abutment carrying bars Hi2 and shafts lit and H3,are carried by, or form structural parts the machine base lid. Bracket iit is slidingly.

engaged with upright guideways M9 on the column and carries aninternally threaded lug i-Zd through which a screw ill passes. Thisscrew is supported by column ill, and may be rotated by hand to raiseand lower the bracket, whereby to accommodate work pieces and grindingwheels of different diameters.

It will be noted that the grinding wheel E22 here shown has an activeface 1 in a plane perpendicular to the spindle M3 to which it issecured, and that this spindl is arranged with its axis horizontal andincapable of adjustment to any other angle. Any desired anguiarity ofthe rolling path of the work piece to the grinding wheel face is bigwheel previously described. Fig. 16 shows graphically how such anadjustment of the cradie causes the work gear to roll on a pitch line plintersecting the grinding wheel face f at the correct inclination to thegrinding wheel face to enerate a. desired curved surface.

Rotation of the carrier 9! is transmitted to the spindle by a notchedindex plate 28 secured to the spindle and a pawl I28 carried by a rockshaft I30, mounted rotatably in the arm 31, which pawl is springactuated to interlock with the index plate. A trigger arm iiil issecured to rock shaft I30 in a location which causes it to engage and.pass a trip I32 as the carrier 'di and connected arm 9'! rock back" andforth.

Trip I32 is adjustably mounted on the housing I33 which encloses theworm tilt, being pivoted to a plate I34 which is adapted to be clampedin difierent positions along a guideway I35, which is secured to housingI33. The trip is-pressed by a spring I36 against a stationary stop onplate I34 with its extremity in the path of the trigger arm I3I. Whenthe trigger passes'the trip in the counterclockwise (with respect toFigs. 18 and 14) roll of the carrier, it is displaced and withdrawstrigger clears the trip, the locking pawl snaps. into the next notch ofthe plate. On its swing in the opposite direction. the trigger displacesthe trip without being itself displaced. By means of the adjustableplate I34, the trip may be placed to accord with work rolling movementsof different extent to cause indexing after the work has rolled clear ofthe grinding wheel.

The grinding wheel of this machine is reciprocated endwise of the work,to distribute its action throughout the extent of wide faced gears andthe 4 oppositely. Worms I45 and I46, of opposite hands,

are mounted on a shaft I41 and mesh with gears I49 and I4! on therespective bars. Shaft I41 may be turned to adjust the rotatable barsand abutments in unison by a handle I50 on a shaft I5I coupled to theshaft I41 by bevel gearing I52.

The cooperative combination and functions of the carrier I35, formersI99 and I40 and abutments HI and I42 are identical with those of thepreviously described combinations of-carrier, formers and abutments, incausing translative displacement of the spindle in a straight pathtransverse to its axis when rotation is imparted to the carrier. Thatpart of the rim of the grind ing wheel which engages the work islikewise displaced-in a straight line. The diagram shown in Fig. andpreviously described demonstrates equally that the center of thegrinding wheel will travel in a straight line corresponding to the linecF-d-d' when .its carrier I is rotated. The

rotary component of motion of the carrier is of no consequence so far asthe rotation of the grinding wheel is concerned, for the latter iscontinuously rotated in one direction. at efllcient speed, which is manytimes more rapid than said rotary component, by a motorv I 59. Thismotor, which is shown in section in Fig. 10, is a hydraulic motor ofknown type and may be like the wheel driving motor 5I shown in Fig. 2and the worm driving motor. I05 shown in Fig. 13.

Of course other types 'of motormay be used in any of these locations.

For so rotating the wheel carrier .oscillatively, a motor I54, hererepresented as an electric motor, ismounted on the machine base anddrives the shaft I by a belt and pulley drive I58.

Shaft I55 is supported by a bracket I51 on a p rt of the machinestructure and carries a crank disk I50 having-a crank pin I59 adjustablysecured at any desired point along a diametral slot I50 in the face ofthe disk. A connecting rod I5I couples the'crank with an arm I52 oncarrier I95 so that, when the crank is constantly rotated inonedirection, the arm is swung back and forth. A stationary guide barI43 occupies tangentially a groove I04 in the. carrier I35 topreventaxial displacement thereof and of the grinding wheel.

, The abutments and their carrier ars, as also bearing structure andmeshes with teeth I59 on the' circumference of the cradle. It may berotated by a handle I69 to adjust the cradle so that the grinding wheelmay be reciprocated in a horizontal path or in sloping paths of variousdegrees of inclination. Thus, for instance, the rim of the grindingwheel may be caused to travelv in the inclined path indicated by thearrows s in Fig. 17, and thereby to grind tapered gears, such as thework piece I10, gear shaper cutters, and

other tapered surfaces.

In order to supplement gravity in maintaining continuous firm contactbetween the formers and abutments of the grinding'wheel carrier, aholddown shoe or slide IN is located over the carrier I38 inbearingcontact with the upper side thereof, and beneath aguide plate I12 whichis supported onopposite sides of the cradle I to bridge over the path oflateral reciprocation of the spindle. In order to permit the smallamount of up and down displacement of the formers I39, I40 and the restof the wheel carrier assemblage, due to change in the inclinations ofthe the guide bar I52, are contained in and supported by a cradle Ihaving an external cylindrical bearing surface, or surfaces, of whichthe axis is parallel to the spindle axis, seated rotatably in astationary bearing I55, which is mounted rigidly on the machine frame.An adjusting screw or worm I01 is mounted rotatably in this abutments,the guide plate may be mounted with provision for correspondingdisplacement. To that end it is here shown as being located on thecradle I65 by a number of headed studs I13, which pass freely throughholes in the guide plate into threaded engagement with the cradle, andsprings I14 may be confined under stress between the heads of the studsand the upper side of the guide plate. Tendency of the carrier andformers to rise from the abutments, due to inertia of the reciprocatingparts of the driving mechanism (connecting rod I 6| and crank arm I62),is thus overcome by the spring pressure, which may be moderate enough toavoid any substantial re'sistancedue to the sliding friction of theshoe- I1I. Similar hold-down shoes may be provided for therolling workcarriers, but in general the weight of these carriers is sufficient, andtheir rate of reciprocation sufficiently slow, to make hold-down meansfor them unnecessary.

The same high quality of accuracy and finish is not required in the caseof the hold-down shoe and its guide, as is required for the guideways ofa sliding work or tool carriage which must reciprocate in an exact pathin order to turnout satisfactory work. Hence essentially the samebenefit is obtained in the case of the wheel carrier by means of itsrolling support of abutments and formers, as is obtained in the case ofthe work carrier.

A'variant of the machine last described is shown in Fig. 18, where agrinding wheel I15, of which the profile, or radial section at thecircumference has the form of a rack tooth, is substituted for theplane-faced wheel I22. Such a wheel has two active faces f and 1", whichare sections of cones taken between planes perpendicular to the axis andthe inclinations of which are opposite to each other. This wheel is ofthe character of that shown diagrammatically in Fig. 20. The spindle;and spindle carrier of this wheel are extended forwardly to a greaterdistance than the corresponding parts of the wheel I22, so as to locatethe mid plane of wheel I15 substantially in radial alinement with themid position of the work holder axis. The wheel spindle holder in thiscase is equipped with formers I39 and I40 and is supported by abutmentsin the same manner, and oscillated by the same mechanism, as describedinconnection with Figs. 7-17, to reciprocate the wheel in exactly thesame manner as there described. For the rest, the

means for the work carriage are mounted directly on the bracket or slideI16, which corresponds to the bracket IIB of the precedently describedmachine.

Figs. 19 and 23 show the application of the wheel-reciprocating means,previously described, to a formed grinding wheel I'I'I, of which thefaces I and I have profiles complemental to the side faces bounding atooth space in a gear, or may be complemental to other shapes to beproduced in a work piece. Here the wheel Ill is located in the sameposition relative to other parts of the machine as in Fig. 18, and itsspindle is contained in a rolling carrier I38 which is rocked anddisplaced in a straight path by means the same as those shown in Figs.7, 8, 10, 1'1 and 12; and the inclination of its path may be changed byadjustmerit of a cradle, as shown in Fig. 17. Hence the precedingdescription of means for supporting,

rolling and adjusting the tool holder apply here' and the constituentparts are identified by the same reference characters used in thatdescriptlonx Inasmuch as the contours required in the work are producedby the form of this grinding wheel I'll, the work is held stationarywhile the wheel acts upon it, and. is rotated only for indexing purposesat times when the wheel is clear of it. Hence the work spindle 92- iscontained in a stationary bearing sleeve "8 supported by a bracket I'I8awhich is slidable and adjustable on a column i I! in the same manner andby like means as the brackets II 6 and I16.

For indexing the work,.a hydraulic motor 98 i and a notched index plateI28 are connected with the spindle I18. A pawl III! is arranged tointerlock with the notches of the index plate, being actuated thereto bya spring I80, and is carried by a rock shaft I8 I, journaled in arm 91,to which also a trigger arm I82 is secured. Spring I80 bears on arm I82.

There is mounted on the bracket I'I8a near the trigger I82 a cylinderI83, in which a piston I85 tion and the port into which supply pipe I90opens is shut oil. The action of cam I94 on the valve body reverses thissituation and connects the supply line with the delivery line, wherebytrip I85 is operated to release the index locking pawl.

Thus indexing of the work is timed by the mechanism for reciprocatingthe grinding wheel, and cam I94 is located to cause indexing when thewheel is at one end of its travel and sumciently displaced from the workto permit rotation of and the tool carrier; and in the machine of Figs.

19 and 23-26 it, is applied to the tool carrier only. This principle isapplicable to machines of other designs adapted to perform various otheroperais reciprocably mounted. The piston carries a trip I and a springI86 bearing on the trip to hold one side of it against a rigid stopshoulder I81. It is able to yield away from the shoulder.

These parts are so arranged that when the piston is raised by accessionof fluid to the lower end of cylinder I83, the trip is carried past theI end of trigger I82, wiping along the adjacent side of the latter anddisplacing it sufllciently to release pawl I19 from the index plate; andcontinuing until it clears the trigger. Motor 98 acts to rotate thespindle-before the locking pawl can return to the same notch, and bringsthe next notch of the disk up to the pawl after the latter has beenreleased by the trip and brought to bear again by spring. I89 on thecircumference of the index plate. yields in passing the trigger;

A control valve I88 is mounted on asupport I89.near the crank disk I59.It contains inlet and outlet ports connected-with supply and returnpipes I90, I9I, respectively, and a delivery port connected by a pipe I92 with the cylinder I83. A valve body I93 is contained in the valve I88with one end protruding for engagement by a j cam projection I94 carriedby 'a crank disk I58. A spring I95 tends to move the valve body I93outward and normally holds it in the'position where the pipes I9I andIf! are in communica- On return of the piston, the trip" tions,wherefore I claim protection for it generically in all forms andcombinations wherein it may be embodied and for all uses to which it maybe applied.

It will be evident to those skilled in the art. without .specificillustration, that rolling means for reciprocating the tool may beapplied also in the design of machine shown in Fig. l, in substitutionfor the sliding carriage II It will be equally apparent that theautomatic indexing means shown in Figs. 9, 13 and 14 may be substitutedfor the manual indexing means of Figs.

1 and 5, with no substantial changes other than possibly of dimensionsand proportions of some of the parts; and that so may the indexing meansof Figs. 23-26, together with suitable provisions for controlling thevalve, like'or equivalent to the controller there shown.

What I claim and desire to secure by Letters Patent is:

1. In a machine,'a carrier and means for supporting and effectingdisplacement of said carrier in a given path, comprising a former inrigid connection with the carrier and extending down wardly therefromhaving opposite convex bounding faces, both of which are curvesgenerated from the same base circle, abutments tangent to the respectiveopposite faces of the former,-said tangent faces of the respectiveabutments being in mutually intersecting downwardly convergent nectionwith the carrier and extending downwardly therefrom having oppositeconvex bounding faces, both of which are curves generated from the samebase circle, two abutments each tangent to one of the opposite faces ofthe former at a point below the center of said base circle.

' said tangent faces of the respective abutments it about a center, andmeans for supporting the-- carrier and transforming the forceapplication into linear displacement of the carrier, consisting of aformer protruding from the ,under side of the carrier, having oppositeconvex faces, and abutments in tangent engagement, each with one of saidfaces, and being inclined convergently toward an intersection beneaththe former.

4. The combination of a carrier, means for applying force to saidcarrier tending to rotate it about a center, and means for supportingthe carrier and transforming the force application into lineardisplacement of the carrier, consisting of a former protruding from theunder side of the carrier, having opposite convex faces which areinvolute curves of a base circle coaxial with said center, and abutmentshaving plane faces each tangent to one of the said faces of the former,said abutment faces being inclined convergently toward an intersectionbeneath the former.

5. A machine combination comprising abutments spaced apart from oneanother and having engaging faces inclined convergently each toward theother, a former having opposite convex faces located between saidabutments with each of said faces in tangent contact with one of theabutments, said faces of the former being curves generated-from a basecircle, a carrier in rigid connection with the former, means formounting a work piece or a tool on said carrier, and means for applyingtorque to the carrier tending to rotate it about the center of said basecircle, whereby the coaction of former and abutments causes displacementof said center in a linear path.

6. A machine for generating curves ina work piece, comprising a workcarrier, means for mounting a work piece on said carrier in a prescribedaxial relation with the carrier, at former in rigid connection with thecarrier having opposite curved faces, two abutments of respectivelyopposite inclinations arranged in tangent.con-

tact, each with one of said former surfaces so as to impart angularmovement to the carrier when the carrier is displaced in a directiontransverse to the abutments and located to support the former andcarrier, means for supporting said abutments, means for .so displacingthe carrier, and an operating tool located in position to act on thework piece mounted on the carrier.

'7. A slideless work holder comprising a carrier,

a former in rigid connection withsaid carrierhaving opposite faces whichare curvesgenerated from a base circle concentric with the carrier andlocated at the underside of the carrier, abutof teeth extending acrossits upper side in a line for securing a work piece to the carrier incoaxial relation with said base circle, and means for exerting force onthe carrier transversely of said axis whereby, through coaction of theformer and abutments, the carrier and work are rolled with a compoundmovement of translation in'a plane and rotation about said axis.

8. In a machine of the character described, a carrierhaving gear teetharranged circumferentially around the upper side thereof, a former inrigid connection with the under side of the carrier extending downwardlytherefrom and having opposite curved faces of which the curvature isgenerated with respect to a base'circle concentric with the axis of thecarrier and the said series of teeth, abutments in tangent engagementwith the opposite faces of the former below the widest part thereofinclined toward one another in the downward direction, constitutingsupporting means for the former and carrier, and a worm rotatablysupported in driving mesh with said teeth; the former and abutmentsbeing disposed to cause translation of the carrier in a straight pathand the engagingside of said wormbeing parallel to said path.

9. In a machine as set forth in claim 6, the combination of means forchanging the inclinations of the abutments, whereby to vary the ratio ofthe translative and rotative components of movement of the carrier.

10. A machine as set forth in claim 6, in which the supporting means forthe abutments comprise a cradle, and a support for said cradle in whichthe latter has a rotative bearing about an axis extending in the samedirection as the axis of the carrier.

11. In a machine, a support having a circular bearing, a cradle mountedon said support adiustably about the axis of said bearing, abutmentsmounted in said cradle spaced apart from one another and inclinedconvergently-downward, a carrier located in the cradle, a former inrigid connection with the carrier at the under side thereof extendingbetween the abutments and having opposite side faces in tangent contactwith the abutments and being wholly supported thereby, the said faces ofthe former being curves of a base circle, of which the axis extends inthe same direction as the axis of the cradle, and a driving elementmounted on the cradle in rotation transmitting engagement with thecarrier.

'12. In'a machine, a support having a circular bearing, a cradle mountedon said support adjustably about the axis of said bearing, abutmentsmounted in said cradle spaced apart from one another and inclinedconvergently downward, a carrier located in the cradle, a former inrigid connection with the carrier at the under side thereof extendingbetween the abutments and having opposite side faces in tangent contactwith the abutments and being wholly supported thereby, the said faces ofthe former being curves of a base circle, of which the axis, in one ofthe positions of the carrier, is coaxial with the bearing surface of thecradle, said carrier having a series concentric with said axis, and aworm mounted on the cradle extending over the carrier in a line parallelto the path of displacement ofthe carrier axis, in driving mesh withsaid teeth.

13. A machine tool comprising a spindle carrier, a work spindle mountedrotatably in said carrier, a lock coupling the spindle to the carrierfor transmitting rotation to the spindle when the carrier is rotated, aformer in rigid connection with the carrier extending downwardlytherefrom having opposite curved faces of which the curves are generatedfrom a base circle coaxial with the carrier and spindle and intersect ata point beeath the center of said circle, inclined abutments underlyingthe former in tangent supporting contact therewith, a tool beneath thespindle axis in position to act upon the under portion of a work piecesecured to the spindle, and means for exerting torque on the carrier,whereby it is caused to roll in non slip relation to a pitch planeestablished by the lines of action between the former and the abutments,and a work piece carried by the spindle is caused to roll across thetool.

14. A machine tool as set forth in claim 13, combined with means foruncoupling the work spindle from the carrier, and means for rotating thespindle relatively to the carrier.

15. A machine tool comprising a spindle carriers being mounted for rier,a work spindle mounted rotatably in said eluding torque exerting meanscoupled with the spindle, a coupling between the carrier and spindle fortransmitting the spindle and including a releasable latch mounted on thecarrier, at former in rigid connection with the carrier extendingdownwardly therefromand having oppositely curved faces, inclinedabutments underlying the former in tangent'contact with said faces andconstituting the support for the foregoing assemblage, said abutmentsbeing disposed to cause lateral displacement of the carrier and spindle,by reaction with said former, when the carrier is rotated about itsaxis, a tool located below a'portion of the spindle in position to acton the under portion of a work piece secured to the spindle, means forrotating the carrier about its axis alternately in opposite directions,and a stationary trip located to act upon said latch in a manner tocausev its release in the course of the lateral movement of the carrier.1

, 16. A machine tool comprising a work spindle carrier, a spindlemounted rotatably in said carrier for indexing, a, tool carrier, one ofsaid carriers being mounted for rolling translative move- ,mentrelatively to the other, a former projecting from the under side of saidrolling carrier having opposite curved contact surfaces, a pair. ofoppositely inclined abutments underlying the former and supporting thesame in tangent contact with said surfaces, means for applying torque tosaid carrier whereby it is shifted bodily in consequence of rollingreaction between said former and abutme'nts, clutching means between thespindle carrier and spindle to prevent rotation of the spindleindependently of the carrier, including a releasable latch, a motor inreactive connection with the carrier and spindle for applying indexingtorque to the spindle, and means for releasing said latch at aprescribed point in the rolling movement of said rolling carrier.

17. A machine tool comprising a work spindle carrier, a spindle mountedrotatably in said carrier for indexing, a tool carrier, one of said carrolling translative movement relatively to the other, a formerprojecting from the under side of said rolling carrier having oppositecurved contact surfaces, a pair of oppositely inclined'abutmentsunderlying the former and supporting the same in, tangent contact withsaid surfaces, means for applying torque to said former and abutments;clutching means between the spindle carrier and spindle to preventrotation of the spindle independently of the carrier,

including a releasable latch, a motor in reactive connection with thecarrier and spindle for applying indexing torque to the spindle, andlatch re-' leasing means controlled by the rolling movement of saidrolling carrier for releasing said latch to permit indexing actuation ofthe spindle by the ment relatively to the other, a former projectingfrom the under side of said rolling carrier having opposite curvedcontact surfaces, a pair of oppositely inclined'abutments underlying theformer and supporting the same in tangent contact with said surfaces,means for applying torque to saidrotation from the carrier to p carrier,a motor secured to the carrier and incarrier whereby it is shiftedbodilyin consequence of rolling reaction between said former andabutments, clutching means between the spindle carrier and spindle toprevent rotation of th'spindle independently of the carrier, including areleasable latch, a motor in reactive connection with the carrier andspindle for applying indexing torque to the spindle, a trip forreleasing said latch to permit indexing rotation of the spindle, andmeans operated by the torque applying mechanism of the rolling carrierfor actuating said trip.

19. A machine tool comprising a work carrier, a tool carrier,cooperative formers and abutments for the respective carriers, of whichthe formers are arranged beneath the respective carriers and theabutments are mounted on the frame structure of the machine beneath andin supporting contact engagement with the respective formers; thecooperating formers and abutments being shaped and arranged to causetranslative displacementof their'respective carriers when torque isapplied to the carriers tending to rotate them; and a tool carried bysaidtool car:

rier in position to act progressively On a work vpiece harried by saidwork carrier.

' translative displacement of said carrier in a given path, comprising aformer in rigid connection with the carrier having opposite convexbounding rolling carrier whereby it is shifted bodily in consequence ofrolling reaction between said placement of the tool carrier and tooltakes place faces, abutments tangent to the respective opposite faces'pfthe former beneath and in supporting contact with the former, and meansfor oscillating the carrier; combined with a tool carrier, a former inrigid connection therewith having opposite curved bounding faces,abutments underlying said former in tangent supporting contact with thefaces thereof, means for oscillating said tool carrier about an axis,and a tool carried by the tool carrier in position to act one work piecesecured to the work carrier.

21. A machine tool for generating wide surfaces of involute curvature,comprising a work carrier, means for displacing bodily and rotating saidwork carrier so that the portion of a work piece carried thereby onwhich an involute curve 1 is to be generated rolls in nonslip pitchcircle relation to a pitch plane, said means comprising a former havingopposite curved faces, the curves of which are involutes of a basecircle coaxial with the prescribed axis of rotation'of the work carrier,inclined abutments supporting said 7 former in tangent contact withthe'opposite faces thereof, and means for imparting rotation to the workcarrier about said axis; a tool carrier,

a tool mounted on said tool carrier having a cutting portion formedto'generate such a curve in a work piece when located to cross thebefore named pitch plane and the work piece is rolled across and incontact with said cutting portion, a former rigidly connected with theunder side of the tool carrier having opposite faces which are curves ofa base circle, abutmentsunderlying said former in tangent supportingcontact with the side faces thereof, and means for exerting force on thetool carrier tangentially of the axis thereof so as to effecttranslative displacement of the carrier by interaction of the former andabutments, the tool carrier and its former and supporting abutmentsbeing so located that the disin a direction substantially parallel to.the axis of the work carrier. 22. a machine tool as set forth in claim21,

spindle carrier, a work spindle rotatably mounted in said carrier forindexing, means for rotati ng said carrier, supporting abutmentsunderlying the carrier and formers rigidly connected to the carrierprojecting downward therefrom into tangent contact with the abutments,said former and abutments'having contact surfaces cooperatively formedand arranged to cause lateral displacement of the carrier and workspindle when the carrier is rotated, a grinding wheel carrier, agrinding wheel spindle rotatably mounted in the last named carrier,supportin abutments un-' derlying the grinding wheel carrier, a formersecured to the grinding wheel carrier extending downward into supportedtangent contact with the last named abutments, the grinding wheelcarrier being located beneath the displacement path of awork piecesecured to said work spindle and the abutments and .former associatedwith the grinding wheel carrier being disposed to cause displacement ofthat carrier lengthwise of the workspindle axis when the carrier isrotated about the axis of the grinding wheel spindle, 'a grinding wheelsecured to said spindle in posi tion to engage at its upper edge withthe under portion of a gear secured to the work spindle, means foroscillating. the grinding wheel carrier, and means for independentlyrotating the grinding wheel spindle. I

24. A machine tool for generating wide curved surfaces, comprising atool carrier, means for moving said tool carrier back and forth in agiven path, a work carrier, a former secured to said work carrierextending downwardly and having opposite curved faces, inclinedabutments underlying said faces in tangent supporting contacttherewith,said abutments being located to support the work carrier over the pathof the tool carrier with provision for rotation of the work carrierabout an axis extending in the same general directionas said path, andwith provision for displacement transversely of said axis. means forrotating the work carrier about said axis and causing lateraldisplacement thereof by coaction of the former and abutments, arotatable cutting tool supported on said tool carrier. with its plane ofrotation substantially parallel to the work carrier axis, and means forrotating said-tool. I

25. A machine tool for generating wide curved surfaces, comprising atool carrier, means for moving said tool carrier back and forth inagiven path, a work carrier, a. former secured to said work carrierextending downwardly and having opposite curved faces, inclinedabutments underlying said faces in tangent supporting'conta'ctftherewith, said abutments being located tosupport the work carrier overthe path of-the tool carrier with provision for rotation of the workearlier about an axis extending imthe same general direction as-saidpath, and with provision for displacement transversely of said axis,means for v rotating the work carrier about saidaxis and causin'glateral displacement thereof by coaction of the former and abutments, arotatable cutting m1 supported on said tool carrier with its plane ofrotation substantially parallel to the work car- 5 rier axis, and meansfor rotating said tool, said tool being adjustable to place its plane ofrota- -tion at various inclinations.

26. A machine tool for generating wide curved surfaces, comprising atool carrier, means for moving said tool carrier back and forth in agiven path, a work carrier a former secured to said work carrierextending downwardly and having opposite curved faces, inclinedabutments underlying said faces in tangent supporting contact therewith,said abutments being located to support the work carrier over the pathof the tool carrier with provision for rotation of the work carrierabout an axis extending in the same general direction as said path, andwith provision for displacement transversely of said axis, means forrotating the work carrier about said axis and causing lateraldisplacement thereof by coaction of the former and abutments, arotatable cutting tool supported on said tool carrier with its plane ofrotation substantially parallel to the work carrier axis, and means forrotating said tool, said abutments being adjustable to differentinclinations sons to vary the extent of lateral displacement of the workcarrier with a given angle of rotation thereof.

27. In a machine tool, a rotatable cutting tool, a spindle to which saidtool is secured, a carrier in which said'spindle is rotatably mounted, aformer secured to said carrier and extendin downward therefrom havingopposite curved faces based on a base circle coaxial with said spindle,abutments having oppositely inclined faces in supporting tangent contactwith the faces of the former, means for oscillating the carrier 40whereby to move it translatively through coaction of the former andabutments, and means for rototing the spindle independently of thecarrier.

28. In a machine tool, a support, a cradle mounted on said support withcapacity for angular adjustment about an axis, a pair of oppositelyinclined abutments mounted on said cradle, a former having oppositecurved faces in tangent rolling contabt with said abutments and beingsupported thereby, a carrier secured to and supported by said former inposition to be-rotated about an axis and displaced transversely of saidaxis when the former is rocked on the abutments,

said axis being substantially parallel to the axis of angular adjustmentof the cradle, and means for imparting motion to the carrier and formerassemblage whereby to rock the same on the abutments.

29. In a machine,,a rotatable carrier and means for supporting saidcarrier with provisions for displacement in a given path, comprising aformer beneath and in rigid connection with the carrier having faceswhich are curves of relatively opposite atures generated from a basecircle, the center of which is coaxial with the axis of rotation of thecarrier, and abutments havin .contact faces inclined to one anotherlocated below'said axis. in tangent supporting contact with the faces,of the former.

EDWARD W. MIILER.

